In a vehicle side-airbag device described in Patent Document 1, an airbag in an inflated and deployed state is provided with a rear side tube bag section extending in the up-down direction further to the vehicle rear side than a vehicle width direction outer side end of the chest of a seated occupant, and a front side tube bag section extending in the up-down direction positioned more to the vehicle front side than the rear side tube bag section and more to the vehicle front side than the vehicle width direction outer side end of the chest of the seated occupant. An upper portion of the rear side tube bag section configures a shoulder restraining section that is positioned at a shoulder side of the seated occupant and restrains the shoulder, and an upper end of the front side tube bag configures an arm support section that is positioned further to the vehicle front side than the shoulder restraining section and lower than an underarm of the seated occupant, and on which the upper arm of the seated occupant rests.
Namely, in the above vehicle side-airbag device, the shoulder of the seated occupant that has relatively high resilience is restrained by the shoulder restraining section, and the upper arm is inhibited from coming between the chest of the seated occupant that has relatively low resilience and the airbag, by resting the upper arm of the seated occupant on the arm support section.